Edythe Scott Bagley, the older sister of Coretta Scott King, has died.

Martin Luther King III said in a statement Sunday that Bagley died Saturday morning at her home in Cheney, Pa.

He says his aunt was a “vibrant, brilliant woman and always a source of strength and wisdom for our mother during the difficult challenges of the civil rights movement.”

Bagley was a retired professor of theatre arts at Cheyney University. She was also an active member of the board of the directors for the Atlanta-based King Center since it was founded in 1968.

The funeral service will be held June 17 at 1 p.m. in Westchester, Pa. Her family is also planning a memorial service celebrating her life in July in Marion, Ala.